Lab Testing When Prescribing Systemic Medication Falls Short of Recommendations

chompoo/AdobeStock

A report in the January issue of JAMA Dermatology reveals that in a recent study, among patients with psoriasis, hidradenitis suppurativa, or atopic dermatitis who were being treated with certain systemic medications, less than 60% received recommended pretreatment testing, including liver function tests and tests for tuberculosis, hepatitis B virus, and hepatitis C virus.¹

The study was a descriptive analysis of 122,308 patients with chronic inflammatory skin diseases starting systemic immunomodulatory treatment in the US.

Researchers Schneeweiss et al ranked the tests performed on these patients from most frequent to least frequent:

• Complete blood cell counts (62%-67%)
• Tests for tuberculosis (46%-60%) and hepatitis (31%-40%)
• Lipid panels (35%-36%)
• Liver function tests (22%-27%)

Testing was at the highest level among patients beginning therapy with tumor necrosis factor α inhibitors, ustekinumab, IL-17Ai, and IL-2.

Schneeweiss et al did not investigate whether these discrepancies in testing affected the success of systemic medication. They commented, “variations in laboratory monitoring practices highlight a divergence from existing testing guidelines; therefore, future work should evaluate whether differential monitoring affects patient outcomes.”

An editorial posted on the JAMA Dermatology site on January 31 discussed the study and posed the questions “Why do we perform laboratory screening and monitoring?” and “In light of the known risks, why are there differences in recommendations?”²

The editorial authors note the guidelines for pretreatment testing are proposed by the US Food and Drug Administration (FDA) and drawn from professional guidelines such as theJoint American Academy of Dermatology–National Psoriasis Foundation guidelines.

They cautioned that many confounders and limitations may have affected the study finding. For example, they wrote, because many of these systemic medications have been available for many years, “the level of comfort with their use is likely high and could result in less frequent laboratory testing.”

“Likewise, differences in state regulations, specifically step therapy, may be associated with whether clinicians order multiple tests upfront while not knowing whether they will be initiating treatment with a biologic or MTX (eg, in the case of patients with psoriasis or those with atopic dermatitis),” they wrote. “It is also possible that clinicians may not know the recommended laboratory screening and monitoring guidelines; therefore, more education of clinicians may be needed. Lastly, it is possible that laboratory testing was performed that was not associated with medication screening and was falsely attributed to screening laboratory results.”

Nevertheless, the primary objective of pretreatment testing in patients undergoing systemic immunomodulatory therapy “is to assess and mitigate potential risks,” they noted, and this study “illuminates the need to elucidate the rationale behind the FDA and professional society testing recommendation practices, as these variations in recommendation might subsequently be associated with patient outcomes.”

References

1. Schneeweiss MC, Shay D, Ly S, et al. Prevalence of pretreatment testing recommended for patients with chronic inflammatory skin diseases. JAMA Dermatol. Published online January 31, 2024. doi:10.1001/jamadermatol.2023.5895
2. Enos CW, Ormaza Vera A, Van Voorhees AS. Clinical data on laboratory testing for patients taking systemic immunomodulatory agents: do we order them enough or too much? JAMA Dermatol. Published online January 31, 2024. doi:10.1001/jamadermatol.2023.5891